Indicator for transitory fluid pulses in a fluid control system



United States Patent [72] lnventor Edward L. l-lolbrook Pinole,California [21] Appl. No. 790,524 [22] Filed Jan. 13, 1969 [45] PatentedNov; 24, 1970 [73] Assignee Amot Controls Corporation a corporation ofCalifornia [54] INDICATOR FOR TRANSITORY FLUID PULSES IN A FLUID CONTROLSYSTEM 7 Claims, 3 Drawing Figs. [52] U.S. Cl. 137/557, l37/625.66,l37/625.69 [5 1] Int. Cl. ..Fl6k 37/00, F 16k 11/07 [50] Fleld otSearch137/557,

[ 56] References Cited UNITEDSTATES PATENTS 3,414,013 12/1968 .laquith137/557 Primary Examiner-Henry T. Klinksiek Attorney-Warren, Rubin,Brucker & Chickering ABSTRACT: In a fluid valve control system of thetype operating in response to a predetermined sequence of transitoryfluid pressure pulses, an indicator is provided for sensing, storing anddisplaying the directional sense of such pulses. For this purpose, anelongate conduit formed of a transparent material is provided withconnections at opposing ends thereof to receive time spaced sequentialpulses of pressurized fluid circulating within the control system, and avisually ob-,

Patented Nov. 24; 1970 Sheet 2 of2 \JLW/ Attorneys Fig.3

INDICATOR FOR TRANSITORY FLUID PULSES IN A FLUID CONTROL SYSTEM Thepresent invention relates to the fluid control art and more particularlytofluid controlsystems employing fluid logic valve devices of the typedisclosed in assignees U.S. Pat. applications Ser. Nos; 707,271 filedFeb. 21, 1968, now Pat. No. 3,516,442, and Ser. No. 723,853, filed Apr.24, 1968.

Fluid logic and/or control systems of the type associated with thepresent invention are designed to operate with a fluid medium andprovide one or more of the functions or operating principlescharacteristic of control systems in general. Such fundamentalprinciples of operation include AND, OR, NOT, NAND/NOR logicas well astime and memory functions. The advantages of these fluid controlsystems-have been demonstrated in a far reaching number of areas, forexample, in the field of automated machinery in which the similaritiesof operation between fluid control systems and hydraulic powerdevices,permit a convenient integration between the control and power functions.

With particular pertinence to the present invention, many controlsystems of this type function in a rather complex sequence of valvingmodes, as for example, in the case of an automated machine where thefluid control system directs and correlates a number of machine partmovements through a complete cycle of operation. This complexity ofoperation both in the control system itself and its servant machine inmany instances make troubleshooting in the case of malfunctionparticularly difficult, particularly where the movable parts of themachine cannot be observed by the operator. The present inventionprovides means in such case to provide a repairman or the operator ofthe machine an immediate visual indication of the instantaneous state orstage of the operating cycle of the fluid control'system, thuspermitting the workman to rapidly determine the disposition of thecontrolled machine parts and to pinpoint theproblem.

While the foregoing is a rather particularized example of the need anddesire for indicating the instantaneous state of a fluid control system,it will be recognized that a number of other purposes may also be servedby providing this information.

Additionally, many if not most control systems of this type involveoperations based on or responsive to'transitory fluid pressures,commonly referred to as fluid'pressure pulses. A typicalexample is foundin systems where a valve is driven back and forth between fluidconducting or fluid-blocking modes by the use of fluid pressureresponsive operators or pilots connected thereto. Duetothe transitorynature of the pressurized fluid signals received by these pilots, it isdifficult if not impossible to determine which valve pilot has .beenactuated last. Again in the case of troubleshooting during repair,installation or otherwise,this lack of information concerning theoperation of the system, greatly complicates and prolongs finding of thedefect or malfunction.

Thus, it is another object of the present invention to provide anindicator capable of sensing, storing and displaying the directionalsense or location of transitory fluid pulses in a fluid control systemand thereby conveniently represent the instantaneous stage of operationof such system. 7

It is a further object of the present invention to provide such asindicator having a few numbers of durable parts and simplicity ofconstruction for low-cost mass manufacture and long trouble free life.

The invention possesses other objects and features of advantage, some ofwhich with the foregoing will be set forth in the following descriptionof the preferred form of the invention which is illustrated in thedrawings accompanying and forming part of this specification. It is tobe understood, however, that variations in the showing made by thedrawings and description may be adapted within the scope of theinvention as set forth in the claims.

In the drawings;

FIG. 1 is a cross-sectional view of the transitory fluid pulse indicatorin combination with a fluid piloted valve, constructed in accordancewith a preferred embodiment of the invention;

FIG. 2 is a cross-sectional view of another indicator identical to theone shown in cross section by FIG. 1 and combined with a similar valveassembly in this instance shown in phantom; and

FIG. 3 is a symbolic circuit diagram of an illustrative fluid controlsystem in which the combined indicators and fluid piloted valves ofFIGS. 1- and 2 may be employed.

With reference to FIGS. 1 and 2, the present invention provides anindicator, indicators 11 and 11a, for sensing, storing and displayingthe location or directional sense of transitory pressurized fluidsignals or pulses, such as occuring in a variety of fluid controlsystems. As used herein, transitory pressurized fluid signals or pulsesrefers to the phenomenon of momentari ly pressurizing fluid in a conduitor within a sealed chamber for the purpose of creating a desiredoperation of the various components comprising a fluid control system.As will become apparent from the disclosure herein, the momentarypressurization of the fluid which forms these pulses is of significancein that the indicator of the present invention not only senses thelocation or direction of such pulses but also memorizes and displaysthis information after the pulse occurrence.

lnorder to achieve these objectives and with reference to I FIG. 1,indicator 11 is comprised in this instance of an'elongated conduit 12having a pair of fittings l3 and 14 suitably connected to each endthereof and providing means for com: municating fluid signals or pulsesbetween a control system and opposing open ends 16 and 17 of conduit 12through passages 18 and 19 of the fittings. In this instance, fittings13 and 14 are connected to communicate passages 18 and 19 respectivelythereofto a fluid piloted valve 21 which as more fully described hereinoperates in response to fluid pulse signals to assume one or the otherof two valving modes. A fluid pressure displaceable member 22 is movabledisposed within conduit 12 and formed with a longitudinal dimensionsubstantially shorter than that of the conduit for shuttling back andforth between opposite ends thereof. This arrangement of conduit 12 andmember 22 forms a bistable fluid-mechanical device in which open ends'l6and 17 provide passages for alternately receiving time spaced fluidpulses from the control system through fitting passages :18 and 19,which displaces member 22' alternately between far right-hand and farleft hand positions within conduit 12. Thus, member 22 within conduit 12has two stable states, one at the right-hand end of and one at the lefthand end, in either of which member 22 will remain until receiving asubsequent fluid pulse driving it to the other stable state at theopposite end of the conduit. As shown in FIG. 1 the last pulse receivedby indicator 11 has been through passage 18 and open end 16 therebydisposing member 22 to its right-hand stable position. Until a pulse isreceived through passage 19, member 22 will remain as shown. Inassociation with this bistable device, conduit 12 is formed of atransparent material and member 22 is formed of an opaque or lightreflective material so as to provide means for visually observing theposition of the latter externally of the former, and thus display theinstantaneous state of the device. In this manner, a quick view ofindicator 11 will immediately inform an operator of the location ordirection of the last fluid pulse occurring in the system, in this case,the last passage of passages 18 and 19 having been so pulsed.

' In the presently preferred embodiment of indicator 11, conduit 12 isprovided by a cylindrical shaped clear nylon tubing which is mountedinto openings 23 of fittings 13 and 14 and sealed and secured therein byferrules 24. Member 22 is formed with a generally elongate cylindricalshape, and coaxially disposed within tubing conduit 12 and provided witha diameter smaller than the inner diameter of conduit 12 so as to permitrelatively free longitudinal movement therein. Preferably, the diameterof member 22 is so dimensioned such that it will interfere with theradially inwardly compressed ends 16 and 17 of conduit 12 caused by thecircumferential compression thereof by ferrules 24 when the indicator isassembled. That is, ends 16 and 17 will exhibit a smaller inner diameterthan the central longitudinal portions of conduit 12.

By this construction member 22 freely slides within the centrallongitudinal regions of conduit 12 whereas its motion will be arrestedand frictionally held at ends 16 and 17 to define terminal positionscorresponding with the right hand or left-hand stable states of thedevice. Additionally, as shown in FIG. 1, member 22 is stopped at aposition with end 26 thereof recessed within conduit 12, such thatpressurized fluid from assage 19 may enter open end 17 and forcefullydisplace member 22 to the left.

As an important feature of the present invention, indicator 11 ispreferably constructed as disclosed herein for operating in combinationwith a fluid operated multiple piloted valve such as valve 21 best showin FIG. 1. A valve of this type is disclosed in detail in above-citedapplication Ser. No. 723,853, and briefly comprises a sectionalizedhousing 27 carrying a central valve portion 28 and a pair of pressurizedfluid actuated pilots 31 and 32 disposed at opposite axial ends of valveportion 28. In operation of valve 21, valve portion 28 is shiftedbetween a far right-hand position as it is shown in FIG. 1 and a farleft-hand position by pilots 31 and 32, respectively, so as to providefluid communication between passages 33 and 34 with a passage 35 ventedin its right-hand position and to provide such communication betweenpassages 34 and 35 with passage 33 vented when valve portion 28 is inthe far left hand position. To effectuate this reciprocation of valveportion 28, pilots 31 and 32 are formed with chambers 36 and 37respectively, which are adapted to receive pressurized fluid throughpilot passages 38 and 39. Communicating with each of chambers 36 and 37are piston members 41 and 42 connected to valve portion 28 and beingindividually responsive to pressurized fluid within chambers 36 and 37,respectively to drive portion 28 to the right or left. For example, itis seen in FIG. 1 that passage 38 has been pressurized driving piston 41to the right and valve member 28 therewith. Accordingly, it may beassumed that pilot 31 has been actuated last. However, as housing 27 inactuality conceals the position of valve portion 28 and piston members41 and 42 from observation, the actual or instantaneous state orposition of valve member 28 cannot be visually determined.

In such a situation a desireable result is obtained in accordance withthe present invention by arranging indicator 11 such that its bistableoperation and visual display is responsive to alternate pressurizationof pilots 31 and 32 of valve 21. As shown in FIG. 1, this isconveniently provided by mounting male portions 43 and 44 of fittings 13and 14 into openings 46 and 47 communicating passages 18 and 19 withchambers 36 and 37 of the respective pilots. In this manner, if valve 21and its associated fluid system are properly operating, indicator 11will sense, memorize and display which of pilots 31 and 32 has last beenactuated and thus indicate the valving mode in which valve portion 28 ispresently disposed. As shown in FIG. 1, member 22 is disposed at its farright-hand terminal position thereby indicating that pilot 31 has beenthe last one actuated. Therefore, passages 33 and 34 should be at thepresent time connected by valve portion 28, which is the case as shownfrom the cross section drawing of FIG. 1. In actual use of course, valveportion 28 is hidden from view and the information as to its positionwould be derived solely from indicator 11.

With reference to FIG. 2, indicator 11a is combined with a fluid pilotedvalve 21a shown in phantom and comprising the same structure as valve 21shown by FIG. 1. However, asindicator 11a is shown with member 22adisposed at the far lefthand terminal position, it will be observed thatvalve 210 is disposed in a state connecting passages 34a and 35athereof, with passage 39a of the right hand pilot (not shown) being thelast to have received a pressurized fluid pulse.

The advantage obtained by sensing, storing and displaying the locationor directional sense of the most recent previous fluid signal or pulseis demonstrated by the control system shown in FIG. 3. The function ofthis system is rather typical broken provides for alternately operatinga plurality of piston carrying, power cylinders 51, 52 and 53, in apredetermined sequence. The resulting motion of piston rods 56, 57, and58 may be used, for example, to operate the various parts of anautomated machine (not shown) in a predetermined or designed sequence.Each of the active components of the system is shown in symbolic form.The symbols indicated within the broken line circles and designated 21'and 21a respectively represent the 3-way fluid piloted valves 21 and 21ashown in FIGS. 1 and 2.

Briefly, the remaining components of the system consist of a pluralityof cam-operated, spring-loaded, 3-way valves 61, 62, 63, 64, 65 and 66,which are arranged in pairs to be operated by piston rods 5658 at thereciprocating limits thereof. A set of 4-way fluid piloted valves 67, 68and 69 provide for supplying pressurized fluid alternately betweenopposite ends of cylinders 51-53 and thereby selectively and forcefullyreciprocate piston rods 5658 between their far right-hand and farleft-hand limits as seen from FIG. 3. Each of valves 67- 69 is formedwith fluid pilots at each end thereof as in the case of valve 21 asshown in FIG. 1 and is commonly referred to as a double piloted valve. Apair of impulse valving devices 70 and 71 are provided and are basicallycomprised of double piloted, 3-way spring biased valves 72 and 73 andfluid flow restricting chokes 74 and 75. These devices function torespond to a pressurization of input conduits 76 and 77 to respectivelyprovide a momentary pressurization of output conduits 78 and 79, suchmomentary pressurization forming a fluid pulse as defined and consideredhereinbefore. A pair of 2-way check valve devices 81 and 82 are providedfor pressurizing conduits 76 and 77 from either of lines 83 or 84 in thecase of check valve 81 and either of lines 85 or 86 in the case of checkvalve 82. The final component consists ofa manually operated 3-way,spring-return valve 87 for turning the system on and off.

Each of the devices and the connecting conduits therebetween areillustrated symbolically wherein the dotted lines represents conduits orvalve connections initially nonpressurized, i.e., vented while the solidlines represent those conduits and valve connections which have beenpressurized from the fluid supply prior to starting operation of thesystem. Also for the purpose of the following description, it is assumedthat the assemblies shown in FIGS. 1 and 2 are connected into the systemof FIG. 3, wherein valve symbols 21' and 21a correspond to valves 21 and21a and wherein the symbolic fluid conduits or lines 90, 91, 92, 93 and94 of FIG. 1 and symbolized conduits 95, 96, 97, 98 and 99 of FIG. 2correspond to conduits of FIG. 3 having the same reference numerals.

In operation of the system, all of piston rods 5658 are initiallyretracted into their left-hand position as shown in the drawing. Toinitiate operation, manually controlled valve 87 is turned on wherebythe following sequence of operation proceeds:

1. Pilot 101 of valve 67 is actuated by pressurized fluid receivedthrough connected passages 34 and 33 of valve 21' and valve 87, therebyconnecting pressurized fluid from the pressurized fluid supply throughvalve 67 to the left-hand end of cylinder 51 and extending piston rod 56to the far right. Limit valve 61 is accordingly released and limit valve62 subsequently actuated.

2. The release of valve 61 releases the pressure in input conduit 76 ofimpulse device 71 via check valve 81 and passage 39a of valve 21a isvented; actuation of limit valve 62 causes passages 38a of valve 21a tobe pressurized thereby piloting this valve to a mode which connectspassages 34a and 33a and with reference to FIG. 2 causes member 220 ofindicator 11a to be displaced to the far right-hand position indicatinga change in valving mode and impulse device 71 is actuated bypressurization of input conduit 76 through line 84 and check valve 81causing a pulse to be issued to conduit 78 thereby actuating pilot 102of valve-68.

3. This operation causes valve 68 to supply pressure to the left-handend of cylinder 52 and extend piston rod 57 to the right which in turnreleases limit valve 63 and subsequently actuates limit valve 64.

' pilot 103 of valve 69 through now communicating passage 34a and 33a ofvalve 21a.

5, Valve 69 now extends pressure to the left-hand end of cylinder 53forcing piston rod 58 to the far right and accordingly releasing limitvalve 65 and subsequently closing limit valve 66. a

6 As limit valve 65 is released, input conduit 77 of impulse device 72is vented through check valve 82 and passage 3 8 of valve 21" islikewise vented; subsequent actuation of limit valve66causespressurization of passage 39 of valve 21' and with reference to FIG, I,shifts valve portion. 28 and member 22 to the left indicating thatpassages 34 and 35 of valve 21 are now connected; additionally, inputconduit 77 to impulse device 72 is pressurized through line 85 and checkvalve 82 causing device ,7 2 to issue a pulse of pressurized fluid topilot 104 of valve 68via conduits79.

7. Valve 68 is thereby shifted extending. pressure to the right-hand endof cylinder 52 and retracting piston rod 57 to the left thus releasinglimit valve 64 and subsequently actuating limit valve 63 again. i

8. As limit valve.64 isreleased passage 34a of valve 21a is vented viaconduit 97; and as limit valve 63 is thereafter actuated, pressurizedfluid is extended to passage 34 of valve 21' via conduit 92 whereuponpilot 106 of valve 67 is actuated via passages 34 and 35 of valve 21 9.Upon this operation, valve 67 shifts the supply pressure to the righthand end of cylinder 51 returning piston rod 5 6.and first releasingvalve 62 and thereafter closing valve 61.

10. As valve.62 is released impulse device 7lis depressurized in amanner as .abovedescribed and passage,38 1 of valve 21a is vented viaconduit 95; thereafter as valve 61 is closed impulse device 71 isactuated to cause a pressure pulse over line 78 reactuating'pilot 102 ofvalve 68.

ll. Pressure is thereby supplied to the; left-hand end of cylinder 52again extending piston rod 57 to the right releasing limit valve 63 andsubsequently actuating limit valve 64.

l2. As limit valve is released passage 34 of valve 21 is vented andthereafter when valve 64 is actuated passage 34a of valve 21a againreceives pressurized fluid which is communicated to passage 35a thereofand via conduit 98 to a pilot 107 of valve 69.

13. By this operation,sthe pressurized fluid supply. is extended to theright hand end'of cylinder 53 by valve 69 to retract piston rod 58 tothe left thereby releasing valve 66 and subsequently actuating valve 65.

14. As valve.66 is released passage 39 of valve 21 isvented and inputconduit77 of impulse device 72 is also vented; and upon subsequentactuation of valve 65 im pulse, device 72 is I actuated sending-a pulseto pilot 194 of valve 68 in a manner as described above; and passage 38of valve 21, is pressurized via conduit 90 and with reference to FIG. 1member 22 is displaced to its right-hand terminal positionalong with andin- .dicating that valve portion 28 is likewise shifted toconnectpassages 33 and 34 of valve 21.

of the system especially in typical cases where piston rods 56 through58 are disposed'internally of the machine in which they operate and arethus hidden from view. Furthermore, even if the instantaneousdisposition of these pistons could be observed at all times, thisinformation will not necessarily aid an operator or service manattempting to locate a malfunction a in the control system it self. Onthe other hand, by virtue of the 6 present invention, a quick view ofindicators 11 and 110 associated with the system as above described,will provide valuable information in this regard.

This advantage is best illustrated by the following chart in which theinstantaneous states of indicators 11 and 11a are correlated with theexpected dispositions of piston rods 56, 57 and 58 if the machine andcontrol system are operating properly.

Pulse Indicator States Member 229. of Positions of pis- Member 22 ofStage of indicator 11 I indicator 112. ton rod 56-58 operation RightLeft 56 Left #1 Start.

57 Left 58 Left Right Right 56 Right #2.

57 Left 58 Left Rf ht Right 56 Right #3 g Right 58 Left Left Right 56Right #4.

57 Right 58 Right Left Right 56 Right #5.

' 57 Left A 56 Left #7. 57 Right 58 Right 56 Left #8. 57 Right 58 Left#1 (repeat cycle).

As indicated by the foregoing chart, the state of indicators 11 and lla, i.'e. the positions of members 22 and 22a,'provide four possiblecombinations, each combination indicating an operating point or stage ofthe system. For example, if indicator 11 shows member 22 to the farright and indicator 11a is disposed with member 22a to the far left, theoperator immediately knows that the cylinder positions are within thefirst orlast stage of operatiori Similarly, if both indicators aredisposed with their members to the left, the operation of piston rods5658 will be between the sixth and seventh stage. This information willbe invaluable in aiding the operator topinpoint a problem For example,where it is attempted to run thesystern through a complete cycle and itis found that one of theindicators does not exhibit a shift in state,the malfunction may immediately be traced to a point upstream fromthatparticular indicator.

1 claim:

1. In a fluid controlsystem having transitory fluid pressure pulses, abistable indicator for storing and displaying the directional sense ofsaid pulses comprising:

an elongated conduit adapted for connection to said system for receivingsaid pulses at longitudinally spaced portions thereof and providing aninterior cylinder wall between said portions; I

a fluid pressure displaceable member mounted for longitudinalreciprocation in saidconduit in response to said pulses;

said conduit and member being formed for frictional retention of saidmember in stable longitudinally spaced positions in the absence of saidpulses to provide memory of the last pulse direction; and

said conduit being at least partially transparent over its length forvisually observing the position of said member therein. 4

2. An indicator as definedin claim 1, stop means disposed atlongitudinally'spaced positions on said conduit defining terminalpositions for said member, said stop means being formed to provide africtional holding of said member.

3. The indicator defined in claim 2, wherein said conduit is formed froma resiliently compressible transparent material and fittings mounted ateach end of said conduit providing said passages and said stop means.

4. An indicator as defined in claim 2 wherein said conduit has taperedportions providing a frictional embrace of said displaceable member todefine said stop means.

5. In a fluid valve control system, the combination comprising; a valveand valving member therefor having first and second positions; a pair offluid actuated pilots operatively connected to said valve, one saidpilot being for displacement of said member to its first position andthe other said pilot being for displacement of said member to its secondposition; bistable fluid-mechanical means having first and second statesand a pair of fluid receiving passages, one said passage being fordisposing said means in its first state and the other said passage beingfor disposing said member in its second state; a pair of fluidconducting means each being connected at one end to one of said pilotsand one of said passages and being adapted for receiving separate fluidpressure pulse signals at the remaining ends thereof; and visuallyobservable means operatively associated with said bistable meansdisplaying the instantaneous state thereof and thus the correspondinginstantaneous position of said member.

6. The combination defined in claim 5 wherein said pilots each have afluid receiving chamber and a piston communicating with said chamber andbeing operated by fluid pressure therein, said passages of said bistablemeans being communicated individually to separate said pilot chambers,and said fluid conducting means being communicated individually toseparate said pilot chambers.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3'542!O65 Dated November 24, 1970 Inventor(s) Edward brook It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 1, line 69, change "adapted" to adopted-.

Column 2 line 34 change "movable" to -movably-.

Column 2, line 45, after "end of", insert -conduit 12-- Column 3, line74, change "broken" to and--.

Column 8, line 21, after "stops for said second" inser member.

Column 8, line 23 delete "a Edward M. Fletcher, Ir. WILLIAM E. SQHUYLBR,JR.

0M Gamissioner of Patents .-A.-. A IRE Jun crn

